joist.

one of a series of parallel beams supporting a floor or ceiling

Use it for

Words that belong together

• floor joist
• exposed joists
• rotten joist

On the page

The floor joist cracked beneath the weight.

Removing the plaster exposed the ceiling joists.

He balanced on a joist above the unfinished room.

Usage notes

Primary curation section: Architecture. Distinguish from a rafter, which is associated with a sloping roof. Plural: joists.